Self-propelled dual-jack hoist

ABSTRACT

A self-propelled, steerable hoist in the nature of a low-bed vehicle especially designed, but not limited, for use to liftfrom beneath and at selected points-a mobile home during the course of placement of said mobile home on blocks at a semipermanent location. The hoist includes a low-level but normally aboveground, elongated bed-frame adapted to be run under the mobile home and then lowered into engagement with the ground for use of the hoist, and a plurality of hydraulic jacks on the bedframe of the mobile home to lift the latter for the purpose described. The jacks are mounted on a powered reversible slide carried by the bed-frame so that the mobile home, as lifted by the jacks, is then positionally adjustable by the slide in the direction of movement thereof.

United States Patent [191 Becker June 18, 1974 [22] Filed:

[ SELF-PROPELLED DUAL-JACK HOIST Aug. 7, 1972 [21] Appl. No.: 278,580

[52] US. Cl. 214/1 D, 214/1 l-l, 254/2 R [51] Int. Cl B25j 3/00 [58] Field of Search 214/1 D, l H, l R, 38 CC,

Pultringer 254/87 Primary Examiner-Frank E. Werner Attorney, Agent, or Firm-Roger B. Webster [57] ABSTRACT A self-propelled, steerable hoist in the nature of a lowbed vehicle especially designed, but not limited, for use to lift-from beneath and at selected points-a mobile home during the course of placement of said mobile home on blocks at a semi-permanent location. The hoist includes a low-level but normally aboveground, elongated bed-frame adapted to be run under the mobile home and then lowered into engagement with the ground for use of the hoist, and a plurality of hydraulic jacks on the bed-frame of the mobile home to lift the latter for the purpose described. The jacks are mounted on a powered reversible slide carried by the bed-frame so that the mobile home, as lifted by the jacks, is then positionally adjustable by the slide in .the direction of movement thereof.

10 Claims, 10 Drawing Figures PATENTEDJun 18 I914 3.81TL401 sum m 0F 4 BACKGROUND OF THE INVENTION During the placement of a mobile home on blocks at a semi-permanent location, it is necessary to lift the mobile home to permit of removal of the transport wheels, and which is then followed by lowering of said mobile home onto blocks. It is currently the practice to lift the mobile home by use of separate, manually operated jacks, and which practice-4n addition to being time-consuming and, hence, uneconomical-produces hazards in that installers must climb under the mobile home in order to place and actuate the jacks. In contemplation of such lack of economy and risk to installers, the present invention was conceived and developed.

SUMMARY OF THE INVENTION The present invention provides, as a major object, a self-propelled, steerable hoist in the nature of a lowbed vehicle especially designed, but not limited, for use to lift-from beneath and at selected pointsa mobile home during the course of placement of said mobile home on blocks at a semi-permanent location; the hoist including a low-level but normally aboveground, elongated bed-frame having support wheels at the front end and coupled at the rear end to a steerable, pusher tractor, such bed-frame being adapted to be run under the mobile home by said tractor and then being lowerable into engagement with the ground for use of the hoist, and a pair of longitudinally spaced hydraulic jacks on the bed-frame are adaptedupon upward extension-to engage the under-frame of the mobile home to lift the latter.

The present invention provides, as another important object, I a self-propelled, steerable hoist, as above, wherein the hydraulic jacks are mounted on a powered reversible slide carried by the bed-frame whereby the mobile home, as lifted by the jacks, is positionally adjustable by the slide in the direction of movement thereof.

The present invention provides, as an additional important object, a self-propelled, steerable hoist that is all-hydraulic; i.e., the propulsion, the steering, and the actuation of the major working parts of the hoist are hydraulically power actuated, and under the control of an operator riding the tractor.

The present invention provides, as a further object, a self-propelled, dual-jack hoist which is designed for ease and economy of manufacture, and minimum maintenance in use.

The present invention provides, as a still further object, a practical, reliable, and durable self-propelled dual-jack hoist, and one which is exceedingly effective for the purpose for which it is designed, and which additionally provides maximum safety, and great convenience of use, while being relatively lightweight and hence easy to transport from job to job.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of the hoist in position below a mobile home, but before lowering of the bedframe to the ground, and prior to extension of the jacks.

FIG. 2 is a like view, but shows the bed-frame as lowered to the ground, and with the jacks extended into lifting engagement with the longitudinal under-frame beams of the mobile home.

FIGS. 3 and 3a are, together, an enlarged plan view of the hoist.

FIG. 4 is a longitudinal sectional elevation taken on line 4-4 of FIG. 3.

FIG. 5 isan enlarged transverse sectional elevation on line 5-5 of FIG. 2.

FIG. 6 is a fragmentary transverse sectional elevation taken on line 66 of FIG. 3a; the view showing-in front elevationthe coupling structure between the bed-frame and the tractor. I

FIG. 7 is a side elevation of such coupling structure.

' FIG. 8 is a sectional plan on line 8-8 of FIG. 7.

FIG. 9 is a rear view of the tractor; the seat and its supporting bar being broken away.

DESCRIPTION OF THE PREFERRED EMBODIMENT an aboveground position and is supported, at its front end, by a pair of transversely spaced, ground-engaging wheels 2. Such wheels are carried on an axle 3 which spans between, and is journaled in connection with, the forward ends of bellcrank levers 4 pivoted, as at 5, on rigid arms 6 which are fixed on, and project forwardly from, opposite sides of the front end of the bed-frame The front wheels 2 are adapted to be simultaneously swung upwardly, to lower the front end of the bedframe 1 to the ground, by means of the following power-actuated mechanism:

A longitudinally extending U-shaped yoke 7 overlies the forward portion of the bed-frame 1 in spaced relation thereabove, and such yoke is pivoted at its front ends, as at 8, to the normally upper ends of the corresponding bellcrank levers 4. At the mid-point of its rear and closed end, the yoke 7 is connected with the front end of the piston rod 9 of a transversely centrally disposed longitudinally extending, double-acting hydraulic cylinder 10. Such power cylinder 10 is attached to, and extends forwardly from, a fixed cross plate 11 spanning in rigid relation between brackets 12 which upstand from opposite sides of the bed-frame 1. It will be recognized thatupon actuation of the power cylinder 10 in a direction to retract the piston rod 9the yoke 7 swings the bellcrank levers 4 in a direction to raise the front wheels 2.

At its rear end, the bed-frame l is vertically adjustably coupled or hitched (by structure hereinafter described in detail, but indicated generally at 13) to a pusher tractor indicated generally at 14.

The pusher tractor 14 comprises a vertical sleeve 15 having a post 16 joumaled therein; such post 16 being formed at its lower end with an offset lag l7, and a single drive wheel 18 is journaled in connection with such leg, with the wheel occupying a position directly below said post 16. The wheel 2 is driven by a reversible hydraulic motor 19 likewise mounted in connection with the leg 17. At the upper end thereof, the vertical sleeve 15 includes a platform 20 on which a reversible hydraulic motor 21 is mounted; such motor being connected to the upper end of the post 16 whereby to reversibly part-turn the latter with resultant steering of the drive wheel 18.

Adjacent but above its lower end, the vertical sleeve is fitted with opposed, outwardly and downwardly inclined, outrigger arms 22, each of which is fitted-on its free end-with a stabilizing wheel unit indicated generally at 23. Each stabilizing wheel unit 23 includes a turnable spindle 24 upstanding from a fork 25; the spindle being journaled in the arm 22. A wheel 26 is journaled in the fork 25, and a helical spring 27 surrounds the spindle 24 between the fork 25 and the arm 22.

As will be apparent from the foregoing, the drive wheel 18 reversibly propels the tractor 14, and consequently the wheel-supported bed-frame 1 in front thereof; such wheel 18 being power-steerable by the reversible hydraulic motor 21 also providing the steering effect for the tractor 14 and said bed-frame.

With the front wheels 2 spaced transversely, and with the tractor 14 provided with the stabilizing wheel units 23, the hoist is effectively maintained against undue lateral tilting when the bed-frame 1 is in its aboveground position The coupling structure between the rear end of the bed-frame l and the tractor 14 (which coupling structure is indicated generally at 13) comprises the following:

At the rear end thereof, the bed-frame l is fitted with a rigid, upstanding, laterally facing hitch plate 28 strengthened by gussets 29; such hitch plate being formed, at its upper and rear end, with a vertical T- shaped slide 30 which engages in a vertical guide member 31 which forms a T-shaped channel for the reception of such slide.

The slide 30 is adapted to be adjusted up and down in the guide member 31 by means ofa vertical, doubleacting hydraulic power cylinder 32 fixed on and upstanding from a platform 33 which projects out from the guide member 31 a distance above the hitch plate 28. At its upper end, the power cylinder 32 is attached to a cross pin 34 which spans between the upper ends of suspension arms 35 connected at their lower ends to the upper edge of the hitch plate 28 by a cross member 36. Thus, upon actuation of the power cylinder 32 to contract or extend the same, the suspension arms 35 are lowered or raised, respectively, resulting in corresponding adjustment of the hitch plate 28, and attendant travel of the slide 30 in the channel of guide member 31. In this fashion, the rear end of the bed-frame 1 is vertically adjustable; i.e., it can be lowered from its normally raised position downwardly to the ground, or lifted from the ground upwardly to said raised position.

For a major portion of its length ahead of the immediate rear end portion thereof, the bed-frame l carries an elongated slide 37 likewise of upwardly opening channel form; the slide 37 having a running fit in the bed-frame l and being held against upward escape therefrom by means of retention strips 38 secured-by boltingto the upper longitudinal portions of the sides of said bed-frame.

Adjacent each of its ends, the slide is fitted with an upstanding, heavy-duty, multi-stage telescopic jack; each such jack being indicated at 39.

The upper stage or section 40 of each jack 39 supports, on its upper end, a swivel cradle 41 having a depending spindle 42 turnably received in said upper section 40', the cradle 41 having a horizontal roller 43 journaled therein. The jacks 39 are spaced apart lengthwise of the slide 37 a distance substantially the same as the transverse spacing of the longitudinal under-frame beams 44 of the body 45 of a mobile home.

The slide 37, together with the jacks 39 mounted thereon, is adapted for powered sliding movement along the bed-frame l, and such movement is accomplished by means of a transversely centrally disposed, longitudinally extending, double-acting hydraulic power cylinder 46 lying below power cylinder 10. At its rear end, power cylinder 46 is anchored to a bracket 47 which upstands from the bed-frame 1 through an elongated slot 48 in the slide 37. A piston rod 49 projects forwardly from the power cylinder 46, and is pivotally connectedas at 50-to the base 51 of the front jack 39. Hence, by operating the power cylinder 46 to retract or advance the piston rod 49, corresponding motion is imparted to the slide 37 on the bed-frame 1 whereby to adjust the jacks 39 in unison lengthwise of said bed-frame 1.

Stabilizing feet 52, in front and rear pairs, are pivoted to opposite sides of the bed-frame 1 in brackets 53; the pivots being indicated at 54. Normally, the stabilizing feet 52 are folded (as in H6. 1) parallel to or close against the sides of the bed-frame 1, but in use of the hoist, and when said bed-frame l is lowered to the ground, said stabilizing feet 52 are swung out (as in H68. 2 and 5) to laterally projecting, ground-engaging positions, and held therein by locking pins 55.

The power cylinders 10, 32, and 46, together with the hydraulic jacks 39 and the motors 19 and 2lbeing all hydraulically actuated-are controlled through the medium of a valve-regulated hydraulic system (the conduits of such system being here omitted, in the main, for the purpose of clarity) which is substantially conventional. Such hydraulic control system is fed from an engine and hydraulic pump unit, indicated generally at 56, mounted on the immediate rear end portion of the bed-frame 1; such engine and hydraulic pump unit 56 including an accumulator tank 57. Additionally, the hydraulic control system includeson each side of the vertical sleeve 15, and on suitable mounting members 58banks of manually operated valves; the valves of the righthand bank being indicated at 59, 60, and 61, and the valves of the left-hand bank being indicated at 62, 63, 64, and 65.

In the present embodiment, the valve 59 controls the reversible drive motor 19; the valve 60 operates the power cylinder 10 to raise or lower the front wheels 2; the valve 61 operates the power cylinder 32 to raise or lower the rear end of the bed-frame l; the valve 62 controls the reversible steering motor 21; the valve 63 operates the power cylinder 46 to move the slide 37 with the jacks 39 thereon; and, lastly, the valves 64 and 64 control, respectively, the front and rear jacks 39.

The tractor 14 includes a rearwardly projecting spring bar 66 which extends from the sleeve 15 intermediate its ends; such barat the rear end-being fitted with a seat 67 for the operator of the tractor. From the seat 67, the operator has-within his ready reach for selective manipulationthe hand levers of the valves 59-65, inclusive.

The self-propelled, steerable, dual-jack hoistas above describedis used in the following manner:

A mobile home is initially provided-intermediate its ends-with wheels for transport; such wheels being here shown singly and diagrammatically, as at 68, for the purpose of illustration. Also, the mobile home includes a front-end hitch (not shown) for coupling to a draft vehicle, and which hitch includes a manual-type jack to support the front end of the mobile home when disconnected from such vehicle. This is the condition of a mobile home when initially rough-positioned preparatory to lifting and setting on blocks, and during the course of which procedure it is frequently necessary to (shift the mobile home laterally;

The vehicle-type hoist of the present invention serves the dual purpose of lifting the mobile home for setting it on blocks, and also to accomplish such lateral shifting of the mobile home as may be requisite to its final positioning.

More particularly, and by way of example, the hoist is manipulated by the operator from the seat 67 so that the normally aboveground bed-frame 1 is run transversely under the rear portion of the mobile home and until the jacks 39 occupy positions substantially alined with the longitudinal under-frame beams 44 of the body 45 of the mobile home.

Nextly, by appropriate operation of the power cylinders l0 and 32 the bed-frame l is lowered to the ground; the feet 52 then being swung out and locked up in their laterally projecting positions, and in which positions they effectively stabilize the bed-frame 1.

With the cradles 41 rotatably adjusted so that the horizontal rollers 43 extend transversely of the longitudinal under-frame beams 44, the jacks 39 are actuated and extended upwardly until the rollers 43 engage such beams 44; this being followed by further extension of the jacks, and which lifts the rear portion of the mobile home a distance necessary for blocking and also for removal of the wheels 68. The rollers 43 in the swivel era'- dles 41 assure against the beams 44 imposing any lateral or side thrust on the jacks 39.

With the rear portion of the mobile home thus lifted, lateral positional adjustment thereof is accomplished by actuation of the slide 37 by the power cylinder 46. As the slide 37 is moved on the bed-frame 1, the jacks 39, and consequently the supported mobile home, are correspondingly moved. It will thus be recognized that lateral adjustment of the lifted portion of the mobile home can be readily and quickly accomplished solely by the operator from seat 67, and without changing the position of the hoist; i.e., the position of the bed-frame 1 on the ground.

After the rear portion of the mobile home has been lifted, laterally adjusted, and then properly blocked, the jacks 39 are contracted, the feet 52 are folded, and the bed-frame I raised to its normal or transport position, whereupon the hoist is caused to travel away from the mobile home and to a point clear thereof.

The above procedure is then repeated-as to lifting, laterally adjusting, and blockingin relation to the front portion of the mobile home, and which completes I the placement thereof.

By reason of the fact that all of the valves 59-65, inclusive, can be readily manipulated by. the operator from the seat 67, all'of the major functions of the hoist,

including travel and steering thereof, raising and lowering of the bed-frame 1, operation of the slide 37, and

actuation of the jacks 39, are accomplished without the operator leaving his position on the tractor. This results not only in substantial economy and efficiency in the setting of a mobile home on blocks, but very greatly enhances the safety of the operation.

From the foregoing description, it will be readily seen that there has been produced such a self-propelled dual-jack hoist as substantially fulfills'the objects of the invention, as set forth hereinf While this specification sets forth in detail the present and preferred construction of said hoist, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention as defined by the appended claims.

I claim:

1. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bedframe secured in connection with and projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, vertically power-adjustable wheels mounted in connection with the front end of the frame, and means coupling the rear end of the frame in vertically power-adjustable relation to the tractor; the

tractor including a steerable drive wheel, there being a motor on the tractor connected in driving relation to said wheel, and another motor on the tractor connected in steering relation to such wheel.

2. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bedframe secured in connection with and projecting forwardly from the tractor, and a plurality of poweractuated jacks supported by the bed-frame in longitudinally spaced relation thereon; the tractor including a single drive wheel, a post on which such drive wheel is journaled, and a sleeve in which the post is turnable; there being outrigger arms projectinglaterally from opposite sides of the sleeve, and ground-engaging wheels journaled on the outer ends of such arms in stabilizing relation to the tractor.

3. A hoist, as in claim 2, including a bar fixed on and projecting rearwardly from the sleeve, and an operators seat on such bar.

4. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bedframe secured in connection with and projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, and a power-actuated slide on the bed-frame reversibly movable in a direction lengthwise of the latter; the jacks being secured on the slide,

the bed-frame being a shallow, upwardly opening chanspaced relation thereon, a power-actuated slide on the bed-frame reversibly movable in a direction lengthwise of the latter; the jacks being secured on the slide, a longitudinal power cylinder disposed adjacent but above the slide, means connecting one end of said power cylinder to the slide, and means connecting the other end of such power cylinder to the bed-frame; said last named means including an upstanding bracket fixed to the bed-frame intermediate the sides thereof, the slide having a longitudinal slot therein and through which the bracket extends.

6. A self-propelled hoist comprising a tractor, an elongated low-level but normally aboveground frame projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, transversely spaced front wheels, means mounting the wheels in connection with the front end of the frame in vertically adjustable relation, power means to so adjust the front wheels in a direction to lower said front end of the frame to the ground, means coupling the rear of the frame to the tractor in vertically adjustable relation, power means to so adjust the rear of the frame in a direction to lower the same to the ground, a slide reversibly movably mounted on the frame for travel longitudinally thereon, and power means to so move the slide; the jacks being mounted on the latter.

7. A hoist, as in claim 6, in which the wheel-mounting means includes longitudinal, transversely spaced, bellcrank levers disposed in parallel and pivoted intermediate their ends on the frame, the wheels being journaled on one end of said levers, and the wheel-adjusting power means being connected between the frame and the other end of the levers in common to the latter,

8. A hoist, as in claim 6, in which the means to adjust the front wheels, the means to adjust the rear of the bed-frame, and the means to move the slide, each include a separate hydraulic power cylinder; the tractor including an operators seat, and manual control valves corresponding to such power cylinders, the valves being within reach of an operator on such seat.

9. A hoist, as inclaim 6, in which the tractor includes a post, a sleeve in which the post is tumable, a single drive wheel journaled in connection with the post beneath the sleeve, a driving motor connected to said drive wheel, a steering motor connected to the post, arms fixed on and extending laterally from opposite sides of the sleeve, and ground-engaging wheels journaled on the outer ends of such arms.

10. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bedframe projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, vertically power-adjustable ground-engaging wheels mounted in connection with the front end of the frame, and means attaching the rear end of the frame to the tractor; such attaching means providing the support for the rear end of the frame and securing said rear end to the tractor in normally fixed but vertically power-adjustable relation, and the tractor including steerable wheel means. l 

1. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bed-frame secured in connection with and projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, vertically poweradjustable wheels mounted in connection with the front end of the frame, and means coupling the rear end of the frame in vertically power-adjustable relation to the tractor; the tractor including a steerable drive wheel, there being a motor on the tractor connected in driving relation to said wheel, and another motor on the tractor connected in steering relation to such wheel.
 2. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bed-frame secured in connection with and projecting forwardly from the tractor, and a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon; the tractor including a single drive wheel, a post on which such drive wheel is journaled, and a sleeve in which the post is turnable; there being outrigger arms projecting laterally from opposite sides of the sleeve, and ground-engaging wheels journaled on the outer ends of such arms in stabilizing relation to the tractor.
 3. A hoist, as in claim 2, including a bar fixed on and projecting rearwardly from the sleeve, and aN operator''s seat on such bar.
 4. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bed-frame secured in connection with and projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, and a power-actuated slide on the bed-frame reversibly movable in a direction lengthwise of the latter; the jacks being secured on the slide, the bed-frame being a shallow, upwardly opening channel beam, and the slide being a plate matingly seating in such beam; there being means to prevent upward escape of the slide from said beam without restricting said lengthwise movement of the slide.
 5. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bed-frame secured in connection with and projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, a power-actuated slide on the bed-frame reversibly movable in a direction lengthwise of the latter; the jacks being secured on the slide, a longitudinal power cylinder disposed adjacent but above the slide, means connecting one end of said power cylinder to the slide, and means connecting the other end of such power cylinder to the bed-frame; said last named means including an upstanding bracket fixed to the bed-frame intermediate the sides thereof, the slide having a longitudinal slot therein and through which the bracket extends.
 6. A self-propelled hoist comprising a tractor, an elongated low-level but normally aboveground frame projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, transversely spaced front wheels, means mounting the wheels in connection with the front end of the frame in vertically adjustable relation, power means to so adjust the front wheels in a direction to lower said front end of the frame to the ground, means coupling the rear of the frame to the tractor in vertically adjustable relation, power means to so adjust the rear of the frame in a direction to lower the same to the ground, a slide reversibly movably mounted on the frame for travel longitudinally thereon, and power means to so move the slide; the jacks being mounted on the latter.
 7. A hoist, as in claim 6, in which the wheel-mounting means includes longitudinal, transversely spaced, bellcrank levers disposed in parallel and pivoted intermediate their ends on the frame, the wheels being journaled on one end of said levers, and the wheel-adjusting power means being connected between the frame and the other end of the levers in common to the latter.
 8. A hoist, as in claim 6, in which the means to adjust the front wheels, the means to adjust the rear of the bed-frame, and the means to move the slide, each include a separate hydraulic power cylinder; the tractor including an operator''s seat, and manual control valves corresponding to such power cylinders, the valves being within reach of an operator on such seat.
 9. A hoist, as in claim 6, in which the tractor includes a post, a sleeve in which the post is turnable, a single drive wheel journaled in connection with the post beneath the sleeve, a driving motor connected to said drive wheel, a steering motor connected to the post, arms fixed on and extending laterally from opposite sides of the sleeve, and ground-engaging wheels journaled on the outer ends of such arms.
 10. A self-propelled hoist comprising a tractor, an elongated, low-level but normally aboveground bed-frame projecting forwardly from the tractor, a plurality of power-actuated jacks supported by the bed-frame in longitudinally spaced relation thereon, vertically power-adjustable ground-engaging wheels mounted in connection with the front end of the frame, and means attaching the rear end of the frame to the tractor; such attaching means providing the support for the rear end of the frame and seCuring said rear end to the tractor in normally fixed but vertically power-adjustable relation, and the tractor including steerable wheel means. 